Sagittal Split Ramus Osteotomy in the Shortest Buccal Bone Marrow Distances of the Mandible on the Coronal Plane

Purpose. This study investigated the relationship between the shortest buccal bone marrow of the ramus and skeletal patterns. Materials and Methods. Using cone-beam computed tomography data (specifically, the A point-nasion-B point (ANB) angle), we divided patients into three groups as follows: skeletal class I ( 0 ° < ANB < 4 ° ), class II (ANB: ≥4°), and class III (ANB: ≤0°). Sixteen vertical sections in the coronal plane were taken starting from slice 0 (original intact mandibular canal) anteriorly at 2 mm intervals to slice 15 (30 mm). The thickness of the mandible (M) and shortest buccal bone marrow (SBM) were measured. The data of SBM were divided into two groups ( SBM ≥ 1 mm and SBM < 1 mm ). For each skeletal pattern, an SBM value < 1 mm was considered to indicate a high possibility of postoperative nerve paresthesia and bad split. Results. The three skeletal pattern groups also did not significantly differ in their M values for all sections. The mean SBM values of class III (0.91–2.11 mm) at 6–16 mm anterior to the mandibular foramen were significantly smaller than those of class II (1.53–3.17 mm). Comparing the occurrence ratio of SBM < 1 mm , the highest and lowest probabilities in class III (55% and 21.7%, respectively) were significantly larger at 6–20 mm anterior to the mandibular foramen than those in class II (28.3% and 5%, respectively). Conclusion. Class III had a significantly shorter SBM distance and higher SBM occurrence probability than class II at the mandibular ramus region, implying that class III participants are more likely than class II participants to have nerve paresthesia and bad split after sagittal split ramus osteotomy.

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Relationship between skeletal Class II and Class III malocclusions with vertical skeletal pattern

Dental Press Journal of Orthodontics ◽

10.1590/2177-6709.24.4.063-072.oar ◽

2019 ◽

Vol 24 (4) ◽

pp. 63-72

Author(s):

Sonia Patricia Plaza ◽

Andreina Reimpell ◽

Jaime Silva ◽

Diana Montoya

Keyword(s):

Class Ii ◽

Class Ii Malocclusion ◽

Class Iii ◽

Class Iii Malocclusion ◽

Multinomial Regression ◽

Lateral Cephalogram ◽

Cross Sectional ◽

Skeletal Class ◽

Skeletal Class Ii ◽

Skeletal Pattern

ABSTRACT Objective: The purpose of this study was to establish the association between sagittal and vertical skeletal patterns and assess which cephalometric variables contribute to the possibility of developing skeletal Class II or Class III malocclusion. Methods: Cross-sectional study. The sample included pre-treatment lateral cephalogram radiographs from 548 subjects (325 female, 223 male) aged 18 to 66 years. Sagittal skeletal pattern was established by three different classification parameters (ANB angle, Wits and App-Bpp) and vertical skeletal pattern by SN-Mandibular plane angle. Cephalometric variables were measured using Dolphin software (Imaging and Management Solutions, Chatsworth, Calif, USA) by a previously calibrated operator. The statistical analysis was carried out with Chi-square test, ANOVA/Kruskal-Wallis test, and an ordinal multinomial regression model. Results: Evidence of association (p< 0.05) between sagittal and vertical skeletal patterns was found with a greater proportion of hyperdivergent skeletal pattern in Class II malocclusion using three parameters to assess the vertical pattern, and there was more prevalent hypodivergence in Class III malocclusion, considering ANB and App-Bpp measurements. Subjects with hyperdivergent skeletal pattern (odds ratio [OR]=1.85-3.65), maxillary prognathism (OR=2.67-24.88) and mandibular retrognathism (OR=2.57-22.65) had a significantly (p< 0.05) greater chance of developing skeletal Class II malocclusion. Meanwhile, subjects with maxillary retrognathism (OR=2.76-100.59) and mandibular prognathism (OR=5.92-21.50) had a significantly (p< 0.05) greater chance of developing skeletal Class III malocclusion. Conclusions: A relationship was found between Class II and Class III malocclusion with the vertical skeletal pattern. There is a tendency toward skeletal compensation with both vertical and sagittal malocclusions.

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Differences in the Buccal Bone Marrow Distance of ≤0.8 mm in the Mandible of Patients Undergoing Sagittal Split Ramus Osteotomy among the Different Skeletal Patterns: A Retrospective Study

Journal of Clinical Medicine ◽

10.3390/jcm10235644 ◽

2021 ◽

Vol 10 (23) ◽

pp. 5644

Author(s):

Yu-Chuan Tseng ◽

Shih-Wei Liang ◽

Szu-Ting Chou ◽

Shih-Chieh Chen ◽

Chin-Yun Pan ◽

...

Keyword(s):

Bone Marrow ◽

Class Ii ◽

B Value ◽

Class I ◽

Occurrence Rate ◽

Class Iii ◽

Sagittal Split Ramus Osteotomy ◽

Lower Lip ◽

B Values ◽

Significant Difference

This study investigated the relationship between the thickness of the ramus and skeletal patterns using cone-beam computed tomography (CBCT) for sagittal split ramus osteotomy. Ninety participants were categorized into three skeletal patterns (Class I, Class II, and Class III). The first vertical slice (slice 0) was observed in the intact mandibular canal, and then moved forward to 40 mm (slice 21) with a 2 mm interval. The thickness of buccal bone marrow (B value) was measured. A B value of ≤0.8 mm was considered to be the major risk factor causing the occurrence of postoperative lower lip paresthesia. There were 461 sides with a B value of ≤0.8 mm. There was a significant difference in the skeletal patterns [Class III (198 sides: 15.7%) > Class I (159 sides: 12.6%) > Class II (104 sides: 8.3%)]. Class II participants had significantly larger B values (2.14 to 3.76 mm) and a lower occurrence rate (≤0.8 mm) than those of Class III participants (1.5 to 3 mm) in front of the mandibular foramen (from 6 mm to 20 mm). Class III participants had significantly shorter buccal bone marrow distance and a higher occurrence rate of B values (≤0.8 mm) than Class II.

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Modifications of Midfacial Soft-Tissue Thickness Among Different Skeletal Classes in Italian Children

The Open Medical Imaging Journal ◽

10.2174/1874347101810010001 ◽

2018 ◽

Vol 10 (1) ◽

pp. 1-8

Author(s):

Daniele Gibelli ◽

Matteo Zago ◽

Annalisa Cappella ◽

Claudia Dolci ◽

Chiarella Sforza

Keyword(s):

Soft Tissue ◽

Soft Tissues ◽

Class Ii ◽

Class Iii ◽

Tissue Thickness ◽

Facial Soft Tissue ◽

Skeletal Class ◽

Soft Tissue Thickness ◽

Italian Children ◽

The Relationship

Background: The anatomical assessment of the arrangement of facial soft tissues has important applications in different fields from orthodontics to plastic surgery. One of the issues concerns the relationship between facial soft tissue thickness and skeletal class. Literature mainly deals with adult populations, whereas very few studies have been focused on children. Objective: This study aims at investigating the relationship between midline facial soft tissue thickness and skeletal classes in Italian pre-treatment orthodontic child patients. Methods: Lateral cephalometric X-ray films were obtained from 220 healthy Caucasoid children (91 males and 129 females), aged between 6 and 18 years (Class I: 41 males and 70 females; Class II: 18 males and 25 females; Class III: 32 males and 34 females). All the films were digitized and 14 soft tissue thicknesses were measured on the midface; in addition, the skeletal class was assessed according to the corrected ANB angle (ANBc). Differences in facial soft tissue thickness according to sex and skeletal class were assessed through two-way ANOVA test (p<0.01). Results: Statistically significant differences according to sex were found for labrale superius, stomion and labrale inferius, with thicker soft tissues in males than in females (p<0.01). Only measurements at labrale superius and gnathion showed statistically significant differences according to skeletal class, with thicker soft tissues in Class III children and thinner ones in Class II children (p<0.01). Conclusion: The limited number of investigations, as well as the differences in protocols, renders the comparison of results from different studies difficult, suggesting further investigations to enlighten this complex and debated anatomical issue.

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Distribution of Pediatric Malocclusion Patients in Seoul National University Dental Hospital

THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY ◽

10.5933/jkapd.2021.48.2.140 ◽

2021 ◽

Vol 48 (2) ◽

pp. 140-150

Author(s):

Sophia Rhee ◽

Ji-Soo Song ◽

Teo Jeon Shin ◽

Young-Jae Kim ◽

Jung-Wook Kim ◽

...

Keyword(s):

Class Ii ◽

Class I ◽

Class Iii ◽

Skeletal Class ◽

Skeletal Class Ii ◽

Therapeutic Decisions ◽

Dental Hospital ◽

National University ◽

Skeletal Pattern ◽

Seoul National University

A total of 580 patients, who visited and received an orthodontic diagnosis in the Department of Pediatric Dentistry, Seoul National University Dental Hospital from 2017 to 2019, were investigated in this study. The aim of this study was to evaluate skeletal patterns of pediatric orthodontic patients determined with lateral cephalometric analysis and to analyze the relationship between skeletal pattern and probable associated clinical features. Also, the modality of orthodontic treatment for each skeletal classification was investigated to aid in therapeutic decisions.<br/>Patients aged 7 year accounted for the largest age group; 54.2% of patients showed a skeletal class I pattern, 22.2% showed a skeletal class II pattern, and 23.6% showed a skeletal class III pattern. Bi-maxillary retrusion for skeletal class I, retruded mandible with normal positioning of the maxilla for skeletal class II, and retrusion of the maxilla with protrusion of the mandible for skeletal class III were the largest subgroups by skeletal pattern. Brachyfacial type accounted for 55.0% of patients, followed by 31.9% of mesofacial type and 13.1% of dolichofacial type. The prevalence of anterior crossbite in the study was 43.3%, higher than that in previous studies.

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The Airway Volume Related to the Maxillo-Mandibular Position Using 3D Analysis

BioMed Research International ◽

10.1155/2021/6670191 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Víctor Ravelo ◽

Gabriela Olate ◽

Gonzalo Muñoz ◽

Márcio de Moraes ◽

Sergio Olate

Keyword(s):

Class Ii ◽

3D Analysis ◽

Class Iii ◽

Cross Sectional ◽

Skeletal Class ◽

Skeletal Class Ii ◽

Mandibular Plane ◽

Mandibular Position ◽

Skeletal Pattern ◽

Maxilla And Mandible

Objective. The aim of this research was to compare three cephalometric analyses and their correlation with the airway volume in subjects with different skeletal classes using 2D and 3D images. Study Design. Cross-sectional descriptive study. Material and Method. Steiner, McNamara, and Ricketts analyses and the airway volume were compared in 115 subjects who were candidates for orthognathic surgery under diagnosis using cone beam computed tomography (CBCT); 46 males (40%) and 69 females (60%) were included. The sagittal positions of the maxilla and mandible, the angulation of the mandibular plane, the sagittal positions of the upper and lower incisors, measurements of the largest or shortest airway area, and the volume were compared using Spearman’s test considering a p value < 0.05. Results. Differences were observed between the Steiner and McNamara techniques for the sagittal position of the maxilla ( p = 0.01 ). For mandibular angulation, there was a greater difference between values for Steiner and Ricketts techniques ( p = 0.001 ). In the upper incisor, the results for McNamara and Ricketts techniques were significantly different ( p = 0.004 ). Analysing the airway, subjects with a class II skeletal pattern had a smaller volume than those with a class III pattern ( p = 0.034 ). Conclusion. It may be concluded that skeletal class II patients have a significantly smaller airway volume than class III patients. The skeletal parameter does not always relate to the airway volume; however, the high mandibular angle could be related to the airway conditions.

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Anatomical characteristics of mandibular bone in skeletal Class I, II and III patients by using cone beam computed tomography images in an iranian population

Brazilian Dental Science ◽

10.14295/bds.2021.v24i2.2475 ◽

2021 ◽

Vol 24 (2) ◽

Author(s):

Mohammad Zandi ◽

Abbas Shokri ◽

Vahid Mollabashi ◽

Zahed Eghdami ◽

Payam Amini

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Class Ii ◽

Class I ◽

Cone Beam ◽

Class Iii ◽

Anatomical Characteristics ◽

Skeletal Class ◽

Skeletal Class Ii ◽

Ramus Height

Objetive: This study aimed to compare the anatomical characteristics of the mandible in patients with skeletal class I, II and class III disorders using cone beam computed tomography (CBCT). Material and Methods: CBCT scans of patients between 17 to 40 years taken with NewTom 3G CBCT system with 12-inch field of view (FOV) were selected from the archive. Lateral cephalograms were obtained from CBCT scans of patients, and type of skeletal malocclusion was determined (Class I, II or III). All CBCT scans were evaluated in the sagittal, coronal and axial planes using the N.N.T viewer software. Results: The ramus height and distance from the mandibular foramen to the sigmoid notch in class II patients were significantly different from those in skeletal class I (P < 0.005). Distance from the mandibular canal to the anterior border of ramus in class III individuals was significantly different from that in skeletal class I individuals (P < .005). Conclusion: Length of the body of mandible in skeletal class I was significantly different from that in skeletal class II and III patients. Also, ramus height in skeletal class I was significantly different from that in skeletal class II patients. CBCT had high efficacy for accurate identification of anatomical landmarks. Keywords Prognathism; Retrognathism; Mandible; Anatomy; Cone beam computed tomography.

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Evaluation of tongue posture & dimensions in relation to skeletal Class I and Class II patterns- A cephalometric study

International Journal of Oral Health Dentistry ◽

10.18231/j.ijohd.2021.054 ◽

2021 ◽

Vol 7 (4) ◽

pp. 276-281

Author(s):

Puja Khanna ◽

Sumit Chhabra ◽

Preeti Munjal ◽

Sunny Mittal ◽

Nishtha Arora

Keyword(s):

Statistical Tests ◽

Class Ii ◽

Class I ◽

Control Group ◽

Skeletal Class ◽

Normal Occlusion ◽

Division 1 ◽

Skeletal Pattern ◽

Bonferroni Test ◽

Class Ii Division 1

Association of tongue posture with dental and facial skeletal pattern have been suggested in past. This study was undertaken to assess tongue posture and dimensions in Class I and Class II Dentoskeletal patterns to determine whether any correlation exists between tongue posture and skeletal pattern of an individual. Cephalograms of 150 individuals (aged 18-23 years), taken in Natural Head Position (NHP) and tongue at rest were divided into three groups i.e. Group 1 – Class I Normal occlusion, Group 2 – Class II Division 1 Normodivergent and Group 3 – Class II Division 1 Hypodivergent, consisting of 50 samples each. To ensure the rest position of tongue, patient was asked to relax for 30 seconds after coating the tongue with barium sulphate in midline and then to swallow, and the X-ray was taken at the end of swallowing. Each group was divided into two subgroups according to sex. Groups were constituted according to the Frankfort mandibular plane angle (FMA) angle. The subjects who had skeletal Class II pattern due to mandibular retrusion and not due to maxillary prognathism were only included in the study group. Statistical analysis was done using the software SPSS version 21.0. The statistical tests used were unpaired t-test and One-way ANOVA test with post-hoc bonferroni test. The p-value was considered significant if less than 0.05.The dorsum of the tongue was higher at back and lower in front in Class II Division 1 Hypodivergent group as compared to Class I Normal occlusion group (P<.05). Tongue height and tongue length were significantly reduced in Class II Division 1 Normodivergent and Class II Division 1 Hypodivergent malocclusion groups when compared to Class I control group (P<.05).The study supports the existence of a relationship between posture & dimensions of the tongue with Class I and Class II skeletal patterns.

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Relationship between skeletal malocclusion and dental anomalies in Nepalese population

Orthodontic Journal of Nepal ◽

10.3126/ojn.v9i1.25684 ◽

2019 ◽

Vol 9 (1) ◽

pp. 15-18

Author(s):

Bashu Dev Pant ◽

Anjana Rajbhandari ◽

Resina Pradhan ◽

Manju Bajracharya

Keyword(s):

Third Molar ◽

Class Ii ◽

Class I ◽

Class Ii Malocclusion ◽

Class Iii ◽

Dental Anomalies ◽

Chi Square ◽

Skeletal Class ◽

Skeletal Malocclusion ◽

Third Molar Agenesis

Introduction: Teeth eruption is important for the development of alveolar process which increases vertical height of the face and third molar is the last tooth to erupt in the oral cavity after birth. The aim of this study was to determine relationship between skeletal malocclusion and dental anomalies in Nepalese population. Materials & Method: A sample of 170 patients with agenesis of at least one third molar was divided into four groups according to the third-molar agenesis pattern. Panoramic radiographs, lateral cephalograph and cast models were used to determine the skeletal malocclusion and associated dental anomalies. The Pearson chi-square test was used for stastical analysis. Result: Among 170 patients more than half of the patients were female with the average age being 18.15 ± 3.64 years. Majority of the patients had Class I skeletal malocclusion followed by Class II and III but on group wise comparison of patients with different skeletal patterns Class I skeletal malocclusion had highest prevalence of dental anomalies followed by Class III and Class II malocclusion. Conclusion: Prevalence of third-molar agenesis was more in skeletal class I malocclusion followed by class II and III but skeletal Class I malocclusions had more dental anomalies followed by class III and class II malocclusion.

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